Two-dimensional materials in perovskite solar cells

Organic-inorganic hybrid perovskite solar cells (PSCs) have experienced a rapid development in the past few years, reaching a certified efficiency over 23%. The semiconducting perovskite materials have shown great potential for photovoltaic applications because of their outstanding optoelectronic properties. Meanwhile, two-dimensional (2D) materials have attracted increasing attention due to their exceptional chemical, electrical and physical properties. Recently, the synergic effects due to the combination of 2D materials and organic-inorganic hybrid perovskite materials have been revealed by many groups. In this review, recent works on the applications of 2D materials in PSCs are comprehensively presented and discussed. The progress and advantages of 2D materials as electrodes, charge transport layers and additives in PSCs are systemically reviewed. Finally, critical challenges and prospects of this research field are addressed.